H-1-NMR of an organic pi-d metal kappa-(BEDT-TSF)(2)FeCl4

We report on H-1-NMR measurements of an organic pi-d metal kappa-(BEDT-TSF) (2)FeCl4, where BEDT-TSF is bis(ethylenedithio)tetraselenafulvalene. C10S4S e4H8. The protons exclusively located at the terminal ethylene are expected to be sensitive to the internal magnetic fields produced by Fe3+ 3d-spins. At high temperatures. the single sharp peak is observed in spectra. Very w ide tails are observed at both sides of the central peak below 4 K, where s pin-lattice relaxation rate T-1(-1) shows the fast and slow components corr esponding to the wide tails and central sharp peak. (C) 2000 Elsevier Scien ce B.V. All rights reserved.